Formvar coated copper grid 150 mesh

At the end of the aggregation reactions, protein solution was diluted to 15 μM by adding the reaction buffer, and the diluted solution (10 μL) was incubated with a Formvar coated copper grid (150 mesh, Electron Microscopy Science) for 5 min. Subsequently, the grid was negatively stained with 1% uranyl acetate for 2 min and washed three times with 1% uranyl acetate. Each time, excess liquid was removed with filter paper. The grid was dried for 48 h. Grids were visualized with a JEOL JEM-2100F transmission electron microscope operated at 200 kV and 600 000× magnification and an Orius Pre-GIF CCD.

For imaging of protein aggregates, a 10 μL (25 uM concentration) droplet from each aggregation experiment was deposited on formvar coated copper grid (150 mesh, Electron Microscopy Sciences) and allowed to sit for 5 min. The excess liquid was removed with filter paper. Grids were then negatively stained for 2 min with 1% uranyl acetate, washed three times with 1% uranyl acetate, each time removing excess liquid with filter paper. The grids were dried for 24 h and then imaged using a JEOL JEM-2100F transmission electron microscope operated using Controller for JEM-2100 v2.18 software at 200 kV, 60,000x magnification, and an Orius Pre-GIF CCD.